Problem: Solve for $x$ : $8x - 8 = 10x + 9$
Solution: Subtract $8x$ from both sides: $(8x - 8) - 8x = (10x + 9) - 8x$ $-8 = 2x + 9$ Subtract $9$ from both sides: $-8 - 9 = (2x + 9) - 9$ $-17 = 2x$ Divide both sides by $2$ $\dfrac{-17}{2} = \dfrac{2x}{2}$ Simplify. $-\dfrac{17}{2} = x$